Liberty misfiring, running rich

Hi guys how's it going so I've got a Jeep Liberty 2005 and I've got some engine misfire/engine running too rich problems. Basically it started off I was driving and I noticed the engine was stuttering a little bit so then I parked it and the check engine light was flashing on and off but didn't stay on constantly I let it sit for a while then I drove it home it drove home fine then the check engine light came back on and stayed on. I then read the codes and it told me there was a misfire in cylinder number 6. I then proceeded to change the spark plugs and coils from cylinder 6 to cylinder 4 erase the codes to see if they would change when it came back on. After doing this I restarted the vehicle let it idle for 15 minutes or so no check engine light no problems I then drove to the store and when I came out of the store to start the vehicle it would not start at all I read the codes again at that point and it said multiple cylinder misfire. Had it towed home and since then I have replaced the crankshaft sensor the camshaft sensor the map sensor the TPS sensor the fuel injectors and I still cannot figure out why it is not running right now after replacing all of this it's still doing the same thing it will not start on its own but if I open up the throttle and give it some air I can get it started but it runs real rich and will not stay idling I know the vehicle is in time because I just had the timing belt replaced and everything redone there and now when I read the code it doesn't say cylinder engine misfire(p300) it says a p172 and a p175 both banks are running rich I'm out of ideas can anyone help thanks.